Răspuns:
[a+ (a+1)+(a+2)+(a+3)+(a+4)+(a+5)+(a+6)]:5=18 rest 1
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care sunt numerele?
[a+(a+1)+(a+2)+(a+3)+(a+4)+(a+5)+(a+6)]=18×5+1=91
1+2+3+4+5+6=21
91-21=70
70:7=10(a)
10+1=11(al doilea nr.)
11+1=12(al treilea nr.)
12+1=13(al patrulea nr.)
13+1=14(al cincilea nr.)
14+1=15(al saselea nr)
15+1=16(al saptelea nr)
